Consider $2$D fully developed laminar flow between parallel plates with gap $10$ mm $.$ The upper plate moves to the right with speed $0\mathrm{.}25\frac{m}{sec},$ while the lower plate moves to the left with speed $0\mathrm{.}5\frac{m}{sec}.$ The pressure gradient in the direction of flow is zero. Obtain the distance d from the lower plate where the velocity becomes zero. Also obtain the volume flow rate per unit depth $\frac{Q}{b}.$ What is $3d\frac{Q}{b}$ in $\frac{m^3}{sec}?$ Choose the closest value. $(4)$

$0\mathrm{.}0025$

$0\mathrm{.}05$

$0\mathrm{.}045$

$0\mathrm{.}0045$